Flexuously compacted conductor



y 5, 1936- J. w. CAMPBELL ,039,475

FLEXUOUSLY GOMPACTED CONDUCTOR Original Filed July 28, 1932 I N VE N TOR. Jaw/v W CAMPBELL ATTORNE Patented May 5, 1936 UNITED STATES PIATENT' OFFICE" Application July 28, 1932,.Serial No. 625,410 Renewed September 25, 1935- 1 Claim.

This invention relates to improvements in flexuously compacted conductors.

The general object of the invention is to provide an electric conductive cable which is formed in spiral shape and may be extended by flattening out the coils which will, when the cable is released, again assume their original position.

Another object of the invention is to provide a coiled electric conductive cable which is formed by coating a plurality of insulated electric conductive wires with 'rubber and winding the resultant product on a mandrel in spiral formation,

then curing the product on the mandrel and thereafter removing the product from the mandrel.

Other objects and the advantages of this invention will be apparent from the following description taken in connection with the accompanying drawing wherein: Fig. 1 is a sideelevation of my improved electrical conductive cable.

Fig. 2 is an end view of the cable. Fig. 3 is an enlarged section taken on line 3-3 of Fig. 2. Fig. 4 is a fragmentary sectional view showing a machine for forming my improved cable.

Fig. 5 is a fragmentary side elevation of the mandrel used in forming my improved cable.

Fig. 6 is a view similar to'Fig. 3 showing a modified form of my invention.

Fig. 7 is a view similar-to Fig. 4 showings nlacline for forming the modification shown in g. Fig. 8 is a view similar to Fig. 6 showing a 85 further modification of my invention.

Fig. 9 is a fragmentary side elevation of a further modified form of my invention.

Referring to the drawing by reference characters I have indicated my improved electrical 0' conductive cable generally at II. As shown the device It comprises an electrical conductive cord l2 which includes a plurality of electrical conductive wires I3 which are encased in and insulated from each other by a casing II which is 45 made of a pliable insulating material such as rubber. The cord l2 maybe of any standard make and may include as many wires It as desired. Surrounding-the casing H of the cord I2 I provide a rubber housing It.

60 In making the device H) the cord i2 is fed into a suitable forming-machine such as indicated at It in Fig. 4 wherein a coating of raw rubber I1 is formed around-the cord II to form the housing II. After the raw rubber H has been posi- 65 tioned on the cord 12 the resultant product is thereafter normally retains its coiled shape as shown in Fig. 1. 10

In use such as when the device III is operatively connected to suitable appliances-to convey electric current'irom a source thereof to an electric iron when the iron is moved. away from source of power the coils of the device l0 will 15 flatten out thereby allowing free movement of the iron and when the iron is move'din the opposite direction the tension of the material of the cable housing ll returns the device it to its initial coiledshape. 20

In Fig. 6 I have indicated a slightly modified form of my inventiongenerally at 20. The device 20 includes an electrical conductive cord II which is similar to the card I! of the device It and comprises a plurality of electrical conductive 25 wires 22 which are encased in and insulated from each other by a casing 23 which is made of a pliable insulated material such as rubber. Surrounding the casing 23 I provide a rubber housing 24 similar to the housing-l5 of the device "L30 Secured to the outer face of the housing 24 I provide a pad member 2! which is formed of rubber of a harder consistency than the rubber which forms the housing 24. Surrounding the housing 24 and covering the pad 25 I have shown a covering 28 which is formed of braided material such ,as cotton threads etc.

In-making the device 2. the cord 2| is fed into a suitable forming machine such as indicated at 21 in Fig. 7 similar to the one shown in Fig. 4. 40

In the machine 21 a coating oiraw rubber 28 is formed around the cord II to form the housing 24. After the raw rubber has been positioned on the cord I! the resultant product and strip of raw rubber 29 which forms the pad 25 is fed onto a rotating mandrel III having a continuous spiral groove 8| therein similar to the groove I! of the mandrel It. The raw rubber 29 which forms the pad 25 is fed onto the mandrel 30 so that it engages the housing 24 on the inside of the coils thereof.

When the mandrel 3! is filled it is removed from the machine 21 and placed in an oven wherein the raw rubber 28 and 28 is cured and at the same --time the rubber 29 becomes vulcanized to the rubber 28. After the device is cured to the desired degree it is removed from the mandrel 30 and thereafter normally retains a coiled shape similar to the shape of the device I shown in Fig. 1. After the device has been removed from the mandrel 30 it is run through a circular braiding machine (not shown) wherein the cover 26 is outer surface thereof.

formed thereon.

By providing the hard rubber pad 2! the coils of the device 20 are stiffer than the coils of the device In and require a greater pull to flatten them and consequently a greater tension is put on the coils which returns them to their initial position when the strain thereon is released quicker than the coils of the device l0 returnto their initial position.

In Fig. 8 I have indicated a further modified form of my invention generally at 32. As shown the device 32 includes an electrical conductive cord as which is similar to the cord I2 of the device I0 and comprises a plurality of electrical conductive wires 34 which are encased in and insulated from each other by a casing 35 which is made of a pliable insulating material such as rubber. Surrounding the casing 36 I provide a housing 38 and surrounding the housing 36 I provide acovering 31 which is formed of a braided material.

The housing 36 is formed of a rubber tubing having a longitudinally extending recess 38 in the In making the device 32 the cord 33 is positioned in the housing 38 and then a rubberstrip 39 is stretched to a predetermined degree and positioned in the groove 31 and chemically vulcanized to the housing 36 while still stretched. After the strip 39 has'become securely connected to the housing 30 the tension on the strip ll is released whereupon it tends to resume its initial unstretched length and in so doing forms the device 32 into coil shape similar to the shape of the device l0.

In Fig. 9 I have indicated another modified form of my inventiongenerally at It]. I The device 40 includes an electrical conductive cord ll which is similar to the cord l2 of the device It and comprises a plurality of electrical conductive wires vulcanized it is removed from the mandrel and thereafter normally retains a coiled shape similar to the shape of the device ill as shown in Fig. i.

In the machine shown in Figs. 4 and 5 the orifice W is tapered and about this orifice is a cylinder IS". A second cylinder I8 is within and concentric with the cylinder IS. The cable I2 is fed through the cylinder 16 while the rubber material is fed through the cylinder W The shaft ii of the mandrel l8 rotates at a speed so that its surface moves at the same rate as that at which the cable with its covering is extruded.

From the foregoing description it will be apparent that I have provided a novel electrical conductive cable which lssimple in construction and highly emcient in use.

Having thus described my invention, I claim:

An electrical cable including an inner flexible helical core, said core comprising a flexible electrical conductor having a flexible insulating covering completely surrounding the same, an outer helical rubber mernber completely covering and surrounding said helical core, a rubber pad extending along the outer surface 0! the outer helical member, said inner helical core, said outer helical member and said pad having the same centerline, said rubber member and said rubber pad being vulcanized in said helical shape and said rubber member being relatively thick with respect to the core, said rubber pad being of harder rubber than the rubber of the outer rubber member whereby the elasticity of the member and pad permits said conductor to be extended when pulled and returns said conductor to ahelical shape when released.

- JOHN W. CAMPBELL. 

